Mathematics Colloquium

Decomposition Towers and their Forcing

When

March 23, 2018 | 2:30 - 3:30 p.m.

Where

Campbell Hall 443

Speaker

Alexander Blokh, UAB and Michal Misiurewicz, IUPUI, Indianapolis

Abstract

We define the decomposition tower, a new characteristic of cyclic permutations. A cyclic permutation π of the set N = {1,…,n} has a block structure if N can be divided into consecutive blocks permuted by π. The set N might be partitioned into blocks in a few ways; then those partitions get finer and finer. Decomposition towers reflect the variety of sizes of blocks of such partitions. Set

4 >> 6 >> 3 >> … >> 4n >> 4n + 2 >> … >> 2 >> 1,

define the lexicographic extension of >> onto towers, and denote it >> too. We prove that if N >> M and an interval map f has a cycle with decomposition tower N then f must have a cycle with decomposition tower M. The results are joint with Michal Misiurewicz (IUPUI, Indianapolis), inspired by the Sharkovsky Theorem, and based upon our (M – B) recent results.


Optimal Quantization

When

February 9, 2018 | 2:30 - 3:30 p.m.

Where

Campbell Hall 443

Speaker

Mrinal Kanti Roychowdhury, The University of Texas Rio Grande Valley

Abstract

The basic goal of quantization for probability distribution is to reduce the number of values, which is typically uncountable, describing a probability distribution to some finite set and thus approximation of a continuous probability distribution by a discrete distribution. Though the term 'quantization' is known to electrical engineers for the last several decades, it is still a new area of research to the mathematical community. In my presentation, first I will give the basic definitions that one needs to know to work in this area. Then, I will give some examples, and talk about the quantization on mixed distributions. Mixed distributions are an exciting new area for optimal quantization. I will also tell some open problems relating to mixed distributions.